Member postings for David Heath 1

I need to replace the motor on my Clarke cl300.

Is there a maximum size of DC motor which can be fitted using the standard control box.

The control board is the old (cj) type.

Hi all.

Many thanks for the suggestions and support, all of which have been most helpful.

Having dismantled the motor and cleaned it, (there was a little swarf inside), the lathe seems to be running OK. The next hurdle will be some parting off of aluminium bar and tubing for my project. Doesn't sound too heavy, but only time will tell. Steady as you go, I suppose.

Dave

Hi S.O.D, Thanks for the support.

After I repaired the board, back in 2013, it ran fine for a few years with a 2amp fuse, till it started blowing them, mainly when parting off. At that time I actually started fitting a 5amp quick blow, which again worked fine for several years, till it went pop recently. Strangely the fuse in the lathe remained intact, it was the mains plug fuse, also 5amp, which blew. It doesn't seem right that I should fit a bigger fuse than the motor rating of 2amp.

Hi all.

Thanks for the suggestions, but I started again from scratch, having sourced a bulk supply of MOSFETs.

I have ended up with a working lathe, jumping various dodgy tracks on the PCB.

The problem is, with a 2amp motor and 2amp fuse, any more than the lightest of cuts results in the fuse blowing. Would this be a rectifier or capacitor at fault?

Logically, I should just replace the board, but I do have the bit between my teeth!

Hiya.

I did source both the pot and the fwd/reverse switch from Arc.

I committed the gravest sin by not transferring the contacts, like for like to the new pot.

I did so religiously, with the fwd/reverse switch.

Best regards Dave

Hi Les.

No problem

Regards Dave

Hi Howard.

Thanks for your reply.

It does seem to be my miss-wiring of the pot.

It was with great trepidation that I switched on for the first time, to be rewarded with a screaming motor.

Regards Dave

Hi Les.

Thank you for the rapid response. I'll check out the relevant wiring when I get back.

Should be straight forward to correct.

My apologies to John Swift. It was his excellent work which enabled me to fix the problem before

Regards Dave

Hi all.

Having followed John Smiths excellent thread on the speed control board, circa 2010, and having run my lathe for around 10 years after the fix, I had another pop/bang and blew the fuse. I replaced both MOSFETs, forward/reverse switch and Pot. The problem is the lathe now works in reverse, i.e. switch on at the wall socket, the lathe runs at top speed. If I then switch on via the pot, then turn it clockwise, the speed reduces and or increases as "normal"

This is a clark cl300 with the old CL250J board. Previously I had to solder in various links where the circuit board tracks had breaks. It has run for about 10 years since, though.

I have a suspicion it could be the MOSFETS which I have miss wired.

I would be most grateful if someone could point me towards the likely explanation.

Regards Dave

Hi.

Well, I'd just like to thank the contributors to this topic,

especially John Swift. Following his advice on the board repairs,

I now have a working lathe.